JPS5920719B2 - Zeolite builder sedimentation prevention method - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for preventing sedimentation of zeolite builder, and more specifically, when a detergent containing zeolite builder is used, used zeolite builder settles into a hard cake in a drain etc. Regarding how to prevent this.

Water-insoluble alkali aluminosilicates such as zeolites are
It has been known for a long time that it has a combination of properties such as excellent metal ion sequestering ability, buffering ability on the alkali side, and re-fouling prevention effect, and that it can be used as a detergent builder by taking advantage of these properties.

However, zeolite builder is water-insoluble and has the property of settling in water, and zeolite builder mixed in detergent may settle in drain pipes or drains that lead laundry wastewater, etc. to sewers and water treatment facilities. There is a concern that this may cause problems such as blockage.

In other words, even though the zeolite particles used as a detergent builder have a relatively fine particle size and have relatively good dispersion stability, once the particles begin to settle, the particles become extremely densely packed together. It has a tendency to form a clunky precipitate cake. If such a hard precipitate cake is formed in a drain pipe or ditch, it is difficult to remove the precipitate cake to the outside, so the flow rate in the drain pipe etc. gradually decreases, and finally This may result in the drain pipe having to be replaced.

Many proposals have been made to improve the dispersibility of zeolite builder particles in water and to prevent the sedimentation of zeolite particles. This relates to the production of a thick zeolite slurry with a zeolite (anhydride basis) concentration of about 30 to 60%, and such a thick zeolite slurry is treated with a nonionic surfactant, a water-soluble polymeric sodium silicate aqueous solution, etc. By incorporating a dispersant, it is intended to prevent the formation of a hard sediment cake due to sedimentation of zeolite particles.

Such conventional proposals are effective in preventing sedimentation when the solid content concentration of zeolite particles is high and the above-mentioned dispersant is also present at a relatively high concentration such as in the slurry state as produced. It was also found that in extremely dilute conditions such as laundry waste water, it exhibits almost no anti-sedimentation effect. That is, the concentration of the washing liquid used in domestic washing machines is relatively dilute, such as 40 tons of detergent per 30 parts of tap water, and when washing, cedar water is used in an amount about three times the amount of the washing liquid. Moreover, considering that such laundry wastewater is discharged into sewage water mixed with other domestic wastewater, in such highly diluted wastewater,
It will be understood that the dispersion stabilizing effect and sedimentation prevention effect of the dispersant cannot be expected at all. The present inventors have discovered that when a mixture of one particle of zeolite builder and a nonionic surfactant whose HLB is within a specific range is dried in the presence of water, one particle of zeolite builder is mixed with the nonionic surfactant. is firmly bound to the nonionic surfactant, and even if this product is dispersed in water again, the nonionic surfactant is retained by the nonionic surfactant without detaching. Even at arbitrary dilution ratios with water, it hardly settles in water, or even if it does, it is only a fluffy, fluffy sediment, effectively eliminating the various drawbacks mentioned above. I found out that it can be done.

Similar effects were found when using long chain alkyl amines.

That is, according to the present invention, crystalline aluminosilicate alkali fine particles having calcium ion exchange ability have an HLB of 6.
A zeolite builder characterized in that a nonionic surfactant or a long-chain alkylamine in the range of 1 to 14 is bonded by drying in an amount of at least 0.1% by weight based on the anhydride of the fine particles. An anti-sedimentation method is provided.

As mentioned above, the important feature of the present invention is that when a specific nonionic surfactant is bonded to one zeolite builder particle, that is, an ion-exchangeable crystalline alkali aluminosilicate fine particle by drying, the nonionic surfactant becomes active. The new finding is that the agent is retained on the surface of each zeolite builder particle without being released even when extracted with water. Figure 1 of the attached drawings shows the relationship between the amount of nonionic surfactant added to zeolite fine particles (vertical axis) and the amount of nonionic surfactant extracted with ethanol from this composition (horizontal axis). It is a line diagram.

If there is no interaction such as bonding between the zeolite fine particles and the nonionic surfactant, the amount added and the amount extracted are 1.
:1 correspondence, which is shown by straight line A. In fact, in a composition in which a nonionic surfactant is added to a slurry of zeolite builder, no matter how long it is left to stand, as shown by the triangular mark △ in Figure 1, the amount of addition and extraction will change. It is recognized that quantity lies on straight line A. On the other hand, in a composition obtained by adding a nonionic surfactant to the slurry of zeolite builder and drying it, the amount of addition and the amount of extraction are in the relationship shown by the circle O in Figure 1, and there is no bending. It is permitted to lie on straight line B.

Comparing this broken line B and straight line A, it can be seen that up to a certain limit amount (approximately 4 to 5% by weight in the example of FIG. 1) of nonionic surfactant is bound to one particle of zeolite builder by drying. It is understood that it is in a state where it does not separate even when extracted with a highly soluble solvent such as ethanol. Therefore, 5 to 1 specified in the present invention
4. In particular, non-ionic surfactants having an HLB (hydrophilic-lipophilic balance) of 7 to 13.5 can be used in combination with other surfactants,
For example, unlike anionic surfactants and other nonionic surfactants, as mentioned above, zeolite builder has a high ability to be bonded and retained by drying, and moreover, it can be stably suspended in water in this bonded state. In addition, it has an excellent property of preventing a hard precipitate cake from forming.

This fact will be easily understood by referring to the example described below. In this specification, HLB has a normal meaning,
That is, when the weight of the nonionic surfactant is 1, it means a value that is 20 times the weight ratio occupied by the hydrophilic groups contained in the molecule, such as polyoxyethylene units and polyhydric alcohols.

If a nonionic surfactant with an HLB value smaller than the above range is used, it will be difficult to stably disperse the treated zeolite builder in water, and a nonionic surfactant with a HLB value larger than the above range will cause the zeolite builder to be dispersed stably in water. It lacks the builder's best anti-sedimentation effect.

As the nonionic surfactant, any known nonionic surfactant can be used as long as it satisfies the above-mentioned limitations.

Particularly suitable nonionic surfactants for the purposes of the present invention have a hydrophilic group selected from the group consisting of polyoxyethylene units and polyhydric alcohols, and a lipophilic group consisting of a long-chain alkyl group, and have an aromatic ring. Suitable examples are as follows.

(i) Polyoxyethylene alkyl ether polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene tallow alcohol ether, (1
1) Polyethylene glycol fatty acid mono- or diester polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monooleate, polyoxyethylene distearate, (1ii) Polyhydric alcohol fatty acid ester resorbitan monolaurate, sorbitan monolaurate Oleate, Stearic acid monoglyceride, 0V) Polyoxyethylene polyhydric alcohol fatty acid esteri Polyoxyethylene sorbitan tristearate, Polyoxyethylene sorbitan trioleate, ()
Polyoxyethylene fatty amine ether.

(I polyoxyethylene fatty amide ether. In the present invention, it is particularly desirable to use a nonionic surfactant as exemplified above, but as an alternative to this,
In the following formula, R is a long-chain alkyl group, particularly a carbon number of 9 to 2
1 alkyl group, and each of R1 and R2 is a hydrogen atom, a lower alkyl group, a hydroxy lower alkyl group, or a group R
It is also possible to use long-chain alkylamines of the formula, such as distearylamine, distearyldimethylamine, oleyldimethylamine, lauryldimethylamine, oleyldiethanolamine.

These nonionic surfactants and long-chain alkylamines can be used alone or in combination of two or more.

It should be noted that the nonionic surfactants used in the present invention are generally less water-soluble than nonionic surfactants used in detergents, but they cannot be used for treatment in a state dispersed in water. I can do it.

In the present invention, the nonionic surfactant and long-chain alkylamine may be used in an amount of 0.1% by weight or more, particularly 0.5% by weight or more, based on the anhydride of the zeolite fine particles. .

That is, if this amount is less than the above range, when the treated zeolite fine particles are diluted with water, there is a tendency that the dispersion stability and sedimentation prevention ability of the zeolite particles cannot be obtained. On the other hand, even if a large amount of nonionic surfactant is used in the treatment, the excess agent will be extracted and transferred into the water as shown in Figure 1.
It is preferably used in an amount of 10% by weight or less, particularly 5% by weight or less, based on the anhydrous zeolite fine particles.
In the present invention, the zeolite fine particles are treated by uniformly bringing the zeolite fine particles into contact with a nonionic surfactant in the presence of water, and then drying the mixture. In this contact operation, the dehydrated water filter cake obtained in the crystallization process is made into a slurry by shear stirring using the moisture contained therein, a nonionic surfactant is added to the slurry, and the slurry is stirred. This is achieved most advantageously. Of course, the dried zeolite powder and an aqueous dispersion or solution of a nonionic surfactant may be mixed and brought into uniform contact with each other. Alternatively, the aqueous dispersion or organic solvent solution of the nonionic surfactant may be sprayed onto the zeolite powder to mix the two. Contact between the two can be sufficiently carried out at room temperature, but if the nonionic surfactant has poor dispersibility in water, heating may be performed to improve the dispersibility. From the standpoint of saving thermal energy during subsequent drying, it is generally desirable to uniformly contact the two in the presence of 20 to 45% by weight of water per zeolite anhydride. In the process of the present invention, as explained with respect to FIG. 1, drying the mixture of zeolite and nonionic surfactant is particularly important in binding the active agent to the zeolite particles.

The exact reason why such a drying process generates bonds that do not break off even when extracted with water is not clear, but since nonionic surfactants have a thick outer hydration layer, they do not bond with zeolite particles in an aqueous system. Whereas strong bonds are difficult to form with ionic surfactants, drying these systems removes this surrounding hydration layer and increases the affinity of zeolites with nonionic surfactants. It is thought that a stronger bond is formed. The drying process according to the present invention can be carried out by any means such as spray drying, fluidized drying, moving bed drying, fixed bed drying, etc., and the drying conditions can be any suitable conditions such as heat drying, air drying, vacuum drying, etc. Yes.

As for the degree of drying, it is sufficient to remove free moisture such as adhered water, and harsh drying conditions such as removing even zeolite water, which is related to ion exchange ability, should be avoided. The treatment of the present invention is applicable to any ion-exchangeable crystalline alkali aluminosilicate particles used as detergent builders. Zeolite for detergent builders has a metal ion sequestering ability of 100 TI on an anhydride basis! CaO bond of 9/y or more (
It is desirable to have a CaO binding capacity of 120 to 180/y.

The ability of zeolite to sequester metal ions differs depending on the type of its crystal structure, and it is known that the ability is A-type, X-type, and Y-type in descending order of ability.

Thus, the zeolite used in the present invention is desirably composed of type A alone or a combination of type A and type X or Y. Also, the metal ion sequestering ability of zeolite The degree of crystallinity is also related to density, and the higher the degree of crystallinity, the greater the sequestration ability.

On the other hand, as the degree of crystallinity increases, the dispersibility of zeolites in aqueous media tends to decrease significantly, but even in the case of highly crystalline zeolites, there is a significant improvement in suspension stability and anti-sedimentation ability. becomes possible. The primary particle size (electron microscope particle size) of the zeolite used is determined by the silicic acid content used in the synthesis,
It varies considerably depending on factors such as the type of raw materials such as alumina, the concentration of alkali metal in the homogenized composition, and crystallization conditions, and generally ranges from 0.1 to 20 microns, especially 0.3 microns.
In the range of 10 to 10 microns. According to the present invention, even when the primary particle size of zeolite is coarse, such as 1 micron or more, significant improvements in suspension stability and anti-sedimentation ability are achieved; A further improvement in the properties is also achieved when the diameter is smaller than microns.
The invention is illustrated by the following example.

Example 1 This example describes a case where zeolite produced by a known method was used to improve sedimentation properties.

100 with heater! Commercially available sodium silicate (Na2O6.9%, SiO222.2%) 19.0% in a stainless steel container
After diluting with 5.0 kg of water while stirring, add a sodium aluminate solution (Na2Ol4.8%, Al2
O3l5. O%) 39.9 kg was gradually added.

After mixing, the mixture was aged for 24 hours with stirring, heated to 90° C., and maintained for 8 hours to produce A-type zeolite crystals.
The synthesis molar ratio at this time is as follows. Na2O/S
iO2=1.65 S102/Al2O3-1.2 Next, filter the reaction solution thoroughly with ・, wash with water and dehydrate to obtain a 9.8k cake with a zeolite anhydride concentration (the same applies hereinafter) of 42.8%.
I got g.

The calcium exchange ability of this zeolite is CaOl56η/
y (anhydrous), the primary particle size was 1-3 microns. This filter cake was made into a slurry by vigorous stirring, and a calculated amount of water was added to prepare a zeolite slurry having a zeolite concentration of 40.0%.

1f of this zeolite slurry 5007? ．． Pour into a stainless steel container and heat to 50'C, and while stirring, heat to 2.0
The nonionic surfactant of No. 7, polyoxyethylene oleyl ether (trade name: Emangen 408), was added and held for 30 minutes. After that, it was dried for 3 hours in an electric dryer at 110'C and sample milled (manufactured by Tokyo Atomizer).
A zeolite powder containing 1.0% of the nonionic surfactant polyoxyethylene oleyl ether on the basis of zeolite anhydride was obtained. This zeolite powder was again dispersed in water to prepare a slurry with a zeolite concentration of 20.0%, and the state of sedimentation was observed. Following the same procedure, experiments were conducted using five types of nonionic surfactants and one type of alkylamine. The results are shown in Table 1. Table 1 also shows the results for two types of nonionic surfactants and one type of anionic surfactant as comparative examples. (Method for expressing sedimentation degree) Approximately 400Tn1 of each of the slurries of Examples and Comparative Examples was placed in a 500ml plastic container and left standing at room temperature for 24 hours.

In this case, a supernatant liquid is produced in all slurries without exception, but since the state of the zeolite concentrated layer below is different, it is expressed as follows. 1: The concentrated layer is divided into two layers, the upper part is soft, but the lower part is hard and cannot be penetrated even with a glass rod.

2...Same as 1, but the lower part can be penetrated by a glass rod if force is applied.

3...The concentrated layer is not so strong that it can be divided into two layers, but when you pierce it with a glass rod, the resistance increases as you go down.

4...The concentrated layer is mostly soft, but there is a slight amount of precipitate at the bottom.

5...The concentrated layer is completely uniform and soft.

Example 2 This example describes a case where the drying method after adding a surfactant was changed.

The nonionic surfactant polyoxyethylene oleyl ether (trade name Emulgen 408) was added to the zeolite slurry obtained in Example 1 (zeolite concentration 40.0%) in the same manner as in Example 1 on an anhydrous zeolite basis. So, 1.0% was added.

This slurry was (A) undried, (B) air-dried (left indoors for 7 days) (0 electric constant temperature dryer (110°C, 3 hours) (D)
Vacuum drying (60°C, -700mmHg 6 hours) (1C)
After drying by spray drying and pulverization, a slurry having a zeolite concentration of 20% was prepared again. Of these, (A) the undried slurry was directly diluted to twice its weight. The sedimentation properties of these slurries were observed and the results are shown in Table 2. As shown in Table 2, it can be seen that although the undried product has a slight effect of preventing sedimentation, the difference is greater than that of the product that has undergone various types of drying.

Example 3 In this example, a case will be described in which the amount of surfactant added is changed.

Using the slurry obtained in Example 1, the nonionic surfactant polyoxyethylene alkyl ether (trade name Liponox N-105) was added on the basis of zeolite anhydride.
0.05%, 0.1%, 0.2%, 0.5%, 1.0%
, 2.0%, and 3.0% were added.Example 1Example 4In this example, the sedimentation property of zeolite after actually being mixed with a detergent and washed is explained.

The zeolite used was produced by the method shown in Example 1 of Japanese Patent Publication No. 55-18479, that is, by mixing sodium aluminate with activated silicic acid obtained by acid-treating acid clay. The obtained water-washed zeolite filter cake was made into a slurry by strong stirring (zeolite concentration 39.5%).
) Add 0.5% of the nonionic surfactant polyoxyethylene oleyl ether (trade name Emulgen 408) based on zeolite anhydride, thoroughly disperse it, adjust the concentration, and spray dry it. It was pulverized in the same manner as in Example 1 to obtain a zeolite powder containing a nonionic surfactant. The properties of the obtained zeolite are shown in Table 4 (Table 4). Next, 15V of this zeolite powder and 500 tons of commercially available granular phosphate detergent, which had been left in a desiccator filled with water for 96 hours to absorb moisture, were placed in a plastic bag and rotated by hand to almost uniformly sprinkle the zeolite over the detergent. Ta. For these test methods, see Japanese Patent Publication No. 18479/1983.

Laundry was carried out using this detergent according to the following standard procedure.

301 water for a commercially available electric washing machine? Add detergent 407 and stir for 10 minutes to dissolve, then wash the clothes to be washed (mainly work clothes made of polyester/polyvinyl alcohol fiber blend)
I added 2k9 and washed for 8 minutes.

After washing, drain the washing liquid from the drain.

This process is repeated 10 times to obtain a large amount of washed laundry liquid, which is collected in a tank, stirred with a stirrer, and left to stand for 48 hours. Next, approximately - of the liquid volume was removed by decantation, water was added to the same level as before, stirred, and allowed to stand again for 48 hours. This operation is repeated five times to remove water-soluble components and collect a concentrated solution of water-insoluble residue from the bottom of the tank. Here too, it was similarly concentrated using the decantation method, and finally 20
The behavior of the residue was observed over a period of 1 month by transferring it to a 0 ml reagent pin. As a result, even after one month, no solid precipitate was observed, and the entire amount flowed out simply by tilting the pin. Example 5 In this example, a detergent containing zeolite was produced as a prototype, and the sedimentation properties of zeolite after actual washing will be explained.

In the same manner as in Example 4, a nonionic surfactant polyoxyethylene oleyl ether (trade name Emulgen 408) was used.
) was added in an amount of 0.5% based on zeolite anhydride, and a detergent having the following composition was prepared using this powder.

Using this detergent, washing was carried out and the water-insoluble residue was collected in the same manner as in Example 4, and its behavior was observed over a period of one month.

As a result, exactly as in Example 4, no precipitation was observed, and the entire amount flowed out simply by tilting the pin.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the amount of nonionic surfactant added to zeolite fine particles and the amount of nonionic surfactant extracted with alcohol.

Claims (1)

[Claims] 1. A nonionic surfactant or a long-chain alkylamine having an HLB in the range of 5 to 14 is added to crystalline aminosilicate alkali fine particles having a calcium ion exchange resin, based on the anhydride of the fine particles. A method for preventing sedimentation of a zeolite builder, which comprises binding by drying in an amount of at least 0.1% by weight. 2. The nonionic surfactant is a nonionic surfactant containing no aromatic ring and having a hydrophilic group selected from the group consisting of polyoxyethylene and polyhydric alcohol and a lipophilic group consisting of a long-chain alkyl group. A method according to claim 1. 3. The method according to claim 1, wherein the nonionic surfactant is added in an amount of 10% by weight or less. 4 Zeolite contains 100 mg/g or more of C on an anhydride basis
The method according to claim 1, wherein the zeolite is a zeolite having an aO exchange ability. 5. The method according to claim 1, wherein the zeolite is A-type, X-type, Y-type zeolite, or a combination thereof. 6. A nonionic surfactant is added to a wet cake of zeolite as obtained by filtration, the composition is subjected to high shear agitation, and the composition is then dried. The method described in paragraph 1.